001    /*
002     * JBoss DNA (http://www.jboss.org/dna)
003     * See the COPYRIGHT.txt file distributed with this work for information
004     * regarding copyright ownership.  Some portions may be licensed
005     * to Red Hat, Inc. under one or more contributor license agreements.
006    * See the AUTHORS.txt file in the distribution for a full listing of 
007    * individual contributors.
008     *
009     * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
010     * is licensed to you under the terms of the GNU Lesser General Public License as
011     * published by the Free Software Foundation; either version 2.1 of
012     * the License, or (at your option) any later version.
013     *
014     * JBoss DNA is distributed in the hope that it will be useful,
015     * but WITHOUT ANY WARRANTY; without even the implied warranty of
016     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017     * Lesser General Public License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this software; if not, write to the Free
021     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
022     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
023     */
024    package org.jboss.dna.graph.sequencer;
025    
026    import java.io.InputStream;
027    
028    /**
029     * The interface for a DNA sequencer that processes a property as a stream to extract information from the content and store in
030     * the repository.
031     * <p>
032     * Implementations must provide a no-argument constructor.
033     * </p>
034     * 
035     * @author Randall Hauch
036     * @author John Verhaeg
037     */
038    public interface StreamSequencer {
039    
040        /**
041         * Sequence the data found in the supplied stream, placing the output information into the supplied map.
042         * <p>
043         * JBoss DNA's SequencingService determines the sequencers that should be executed by monitoring the changes to one or more
044         * workspaces that it is monitoring. Changes in those workspaces are aggregated and used to determine which sequencers should
045         * be called. If the sequencer implements this interface, then this method is called with the property that is to be sequenced
046         * along with the interface used to register the output. The framework takes care of all the rest.
047         * </p>
048         * 
049         * @param stream the stream with the data to be sequenced; never <code>null</code>
050         * @param output the output from the sequencing operation; never <code>null</code>
051         * @param context the context for the sequencing operation; never <code>null</code>
052         */
053        void sequence( InputStream stream,
054                       SequencerOutput output,
055                       SequencerContext context );
056    }